Fix build failure introduced by r10380

test/cctest/test-heap.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 
 #include <stdlib.h>
 
 #include "v8.h"
 
 #include "execution.h"
 #include "factory.h"
 #include "macro-assembler.h"
 #include "global-handles.h"
@@ skipping 1463 matching lines @@
   CHECK_EQ(2, NumberOfGlobalObjects());
   ctx2.Dispose();
   HEAP->CollectAllAvailableGarbage();
   CHECK_EQ(0, NumberOfGlobalObjects());
 }
 
 
 TEST(InstanceOfStubWriteBarrier) {
   if (!i::FLAG_crankshaft) return;
   i::FLAG_allow_natives_syntax = true;
+#ifdef DEBUG
   i::FLAG_verify_heap = true;
+#endif
   InitializeVM();
   v8::HandleScope outer_scope;
 
   {
     v8::HandleScope scope;
     CompileRun(
         "function foo () { }"
         "function mkbar () { return new (new Function(\"\")) (); }"
         "function f (x) { return (x instanceof foo); }"
         "function g () { f(mkbar()); }"
@@ skipping 30 matching lines @@
     v8::HandleScope scope;
     v8::Handle<v8::Object> global = v8::Context::GetCurrent()->Global();
     v8::Handle<v8::Function> g =
         v8::Handle<v8::Function>::Cast(global->Get(v8_str("g")));
     g->Call(global, 0, NULL);
   }
 
   HEAP->incremental_marking()->set_should_hurry(true);
   HEAP->CollectGarbage(OLD_POINTER_SPACE);
 }